Match two excel spreadsheets

We have two excel spreadsheets that are not exactly aligned: the Master has approximately 9700 rows and the table to be aligned has >11000. We need to match as many as possible of the TableAm rows using any technique available to you, though common ones such as index/match, vlookup and soundex will be handy if you know them. Based on previous experience, the job will take about 6-8 hours. There are multiple criteria required to match each row and the final result will be 90-100% successful matches to the \'Master\' supplied. Accuracy of successful matches is critical, and the preference is accuracy over completeness.

The objective is to match the unique id of the TableAm product table to the MASTER, using the fields available to the closest match.

The variables that need to match are Name, Form, Strength & PackSize